This invention relates to apparatus for threading the ends of a rod, or like member, either externally or internally; and more particularly to such apparatus which is semi-automatic in operation.
Machines which are conventionally used for the cutting of external threads on the ends of rods are turret lathes. Such machines are very expensive from the standpoint of equipment investment, and are expensive machines to operate from the standpoint of the labor time required to insert and remove work pieces and that a highly skilled machinist is required for the operation of such machines. Such machines are inefficient for threading a production run of rods because they are not geared to high speed production, and they are also limited to the threading of a single length of thread without time consuming and expensive setup changes. For the cutting of threads on a rod in a production run, whether it be a long production run or a short production run, it is desirable to provide a threading machine which is capable of high speed operation and which is adapted to be operated by semiskilled personnel. Since threaded rods may require different lengths of thread on the opposite ends thereof, it is desirable to provide a rod threading machine which is capable of threading, sequentially, both ends of the rod, and which is automatic in this regard so that time consuming setup is not required.
A principal object of this invention is to provide apparatus for threading the ends of rods, which apparatus is semi-automatic in operation enabling fast and accurate threading operation by unskilled personnel.
Another object of this invention is to provide such apparatus wherein the only steps by the operator include inserting a rod into the chuck, moving the rod and chuck forward into engagement with the threading head, and withdrawing the rod after the threading is completed.
A further object of this invention is to provide such apparatus which is simple to use, and enables the precise threading of a selected length of threads on a rod with minimal opportunity for error.
Still another object of this invention is to provide such apparatus which is compact in design and portable in the sense that it can be readily mounted or supported on any suitable support frame or table.
A still further object of this invention is to provide such apparatus which is portable and self-contained, thereby readily moved to different work locations and set up for immediate use.
Another object of this invention is to provide such apparatus which can be set up to cut different lengths of threads on opposite ends of a rod, in alternating apparatus cycles.
Another object of this invention is to provide such apparatus wherein the length of threads to be cut can be set very precisely; and where the length of threads to be cut can be changed very easily and quickly.
Another object of this invention is to provide such apparatus for the cutting of long threads on a rod in multiple increments, and for cutting of a full length thread on a rod.
These objects are accomplished broadly in threading apparatus which comprises the following components mounted on a support base. A hollow drive spindle is mounted for rotation on the base, and a threading head is nonrotatably mounted on the drive spindle in axial alignment therewith. Drive means is provided for rotating the drive spindle in at least one direction. A carriage is mounted on the base for forward and rearward reciprocating movement in a direction parallel to the rotational axis of the threading head. Stop means limits the rearward movement of the carriage away from the threading head, and defines a rear limit position for the carriage. A collet chuck is mounted on the carriage disposed in axial alignment with the threaded head; and the carriage and collet chuck are configured to enable a rod to be passed through the chuck. Actuator means are mounted on the base for controlling selected functions of a threading cycle of the apparatus; and trip means is mounted on the carriage for activating the actuator means in response to selected movements of the carriage.
More particularly the apparatus may include a self-opening and closing threading head, a self-opening and closing collet chuck, and/or an automatically reversing drive means for the spindle; and the actuator means are provided for controlling selected functions after the carriage moves a selected distance toward the threading head, and upon return of the carriage to the rear limit position.
The novel features and the advantages of the invention, as well as additional objects thereof, will be understood more fully from the following description when read in connection with the accompanying drawings.